The Early Adult Reduction of weight through Lifestyle (EARLY) Consortium includes several randomized controlled intervention trials designed to reduce weight or prevent unhealthy weight gain in young adults. Each of 7 participating sites across the United States developed their own intervention(s) using a variety of behavioral change techniques and including technologies used by young adults. Thus, there is heterogeneity in the interventions across the studies. However, the investigators agreed to common elements across all of the studies such as some common measurements, including outcomes, and aspects of the data collection protocols. This model whereby multiple interventions are funded to test several approaches for a health outcome using a set of common elements has been increasingly used by various institutes within the NIH. This approach has great potential to advance knowledge beyond what could be learned from the individual research studies by combining information across studies in a meaningful way. The EARLY studies have a Resource and Coordination Unit (RCU) that maintains a common database to which all of the studies contribute and which facilitates cross-study analyses. Complex interventions commonly employ various techniques for behavior modification, and it is not always the case that all techniques contribute to intervention success. End results of controlled clinical trials may indicate that an intervention package worked better than a control condition, but little other specificity regarding the theory based techniques that led to intervention success may be available. This application will use an innovative process to identify behavioral techniques across studies that lead to successful weight loss. Specifically, the approach to be implemented is to measure the extent to which behavior change techniques are employed by each of the EARLY interventions and to use those measures in conjunction with measures of intervention intensity in a manner similar to a process previously used successfully by another consortium of independent but coordinated randomized controlled trials. The long-term objective is to identify the theory-based behavior change techniques that lead to successful weight loss in young adults in this group of interventions. Another goal of this project is to develop, test and disseminate the process used to identify the most promising techniques across this consortium of studies. Hence, the goals of this project are to identify basic discoveries about intervention components related to weight loss and to disseminate the information to scientists, physicians, and ultimately the public.